Astrophotography Tutorial: How to Remove Gradients in Photoshop

[@CosmosSafari]

Trevor, I just did this method and it BLEW MY MIND. Thank you, buddy. It just saved my image from being a complete waste of time.

[@BobRobertsons]

What I usually find helpful is to use Select -> Colour Range -> Highlights to select the stars, and then do a content-aware fill. I find it works better than not removing the stars and just doing dust and scratches.

[@AstroBackyard]

+Richard Hum That's an excellent tip Richard, thank you!

[@jwbullardxxiii]

@@AstroBackyard Could you expand on this method? I'm not quite sure how to make this one work.

[@strandbj]

@@jwbullardxxiii I find this works best if after you select a clearly definable star, then MODIFY the selection by EXPANDING it enough pixels to surround the star halo, then select SIMILAR to get the other stars. Then select EDIT > FILL and make sure the dialog box shows CONTENT AWARE (which I think is the default). Blend mode is NORMAL and opacity is 100%. Click Okay. The computer will work for a few seconds analyzing the entire picure surrounding each selection and apply what it thinks is the average. This isn't flawless and you will have to clean up a few areas, but it works well. I do think the healing brush method gives you better control, but this does work great when you have a lot of stars you want to erase.

[@RScottDuncan]

I'm new to astrophotography and this was so very helpful. New subscriber. Thanks.

[@divyanshkataria6235]

I think you're the best astrophotographer on the planet🌍❤

[@AstroFarsography]

Trevor, this video is amazingly undervalued. Always keep coming back to this when my flats don't do quite a good enough job. Cheers for making this.

[@GregoryK-IYA]

I find that content aware fill can introduce details that will layer become visible in further stretching. So I also apply a bit of Gaussian blur to the layer after dust removal step and I don't subtract with apply image, I give the layer a subtract blend mode and vary opacity for amount of subtraction. Very non-destructive and I can always come back and redo this step if I find anomalies later.

[@matthewbrown8679]

Also after watching this the first time I tried this in a different order; I did the scratch and dust removal first, then used the healing brush as needed. Makes it easier to grab a reference area.

[@Harpiarz]

Finally! More tutorials for PS!

[@AstroBackyard]

and more on the way... thanks!

[@CaptainOnePocket]

Awesome. Thanks for sharing this Astrobackyard. You've inspired me to get a "real" telescope and I know now I can enjoy this in my own backyard even though I live in a big city (Minneapolis). Keep up the good work. I wish you all the best.

[@johnheyes5287]

Hi I've been following you channel for some time now and have found your tutorials very helpful. In this video at around 7 mins you make a new layer. How did you do this. When I add a new layer its blank!!

[@AnkitGupta12]

I was going to go for the GradientXterminator tool , but by seeing this , I will try to work on my images. A quick question, can you help me in removing the gradient from wide astrophotography images (18 - 50 mm)? With some change on this procedure, I think we can do it

[@vpsjdon]

Can you please help me do this in the case of wide field Milky Way shots? When I try to do this, I can't remove the structures of the milky way using the clone brush or the spot fixing tool. It just leaves an extremely weird void in place of the Milky Way(even after using the dust and scratches thing). After subtracting the "blurred" image from the main image, I do get less gradients, but the Milky Way loses a lot of details as well. It starts looking like it was carved in the sky. Can you please give me any tips or suggestions to tackle gradients in Milky Way shots? Thank you :)

[@lukewearphotography1254]

Awesome tutorial! Still works great!

[@jujubean7664]

This was incredibly helpful. Thank you!

[@andyweeks2216]

This is a fantastic help Trevor!!! Thank you!

[@fredangeli5618]

Great presentation, I have a number of photo I can now get to work on. Keep up the great job!!!!

[@davehart4812]

Really, *really*, **really** helpful video!!! Thanks for sharing this, it's given me renewed hope with image processing! 👍

[@jaimie_t]

Thank you for this! This is very helpful to absolute beginners (like me). It helps me drastically improve my first photos which I just took the past few weeks without flats (I didn't realize how important they are). I'm using Hyperstar and the t-shirt method doesn't work for that method. I'm trying to figure out flats with hyperstar now.

[@rockdv75]

Hi Trevor, can you use this method with a bigger target like the seagull nebula? And do you still erase the dso the same way?

[@matthewbrown8679]

Hey Trevor, thanks for the video. I'm guessing if you are resorting to this method the gas tail of the hamburger galaxy is gone? Though I'm guessing you might start with a quick mega-stretched image just to see where the tail is, put your mega-stretched image below your gradient remover, put the gradient remover at low opacity so you can see what's beneath it, but still see the effects of editing it, and take the healing brush to the gas tail. Then delete the mega-stretched image and do your subtraction.

[@budgetastrophotography1506]

Thanks, your PS tutorials has been a great help keep them coming

[@Beespin]

Great Video! Im having issues trying to use my T-Ring + Adapter and a 5mm + 2x Barlow to get focused. I can't tell if the 5mm lens is too far from the camera sensor, or if the whole adapter + camera is too far from the telescope. Can someone help me out?

[@ivanpierce479]

Another banger...thank you!

[@Max6785]

Excellent video...this did the trick for me where gradient Xterminator and Startools wouldnt! Thanks for posting!!

[@allenlloyd1074]

That’s very clever. Thank you.

[@davidaylsworth8964]

Great video! Another tool in the toolbox.

[@greatvaluegalileo]

Love all the videos but I got stuck. When trying to apply image the only option in the drop down menu is my main image and the synthetic flat I made doesn't appear in the list at all. I've tried saving the flat, I've tried closing and reopening PS. Any suggestions what to try next?

[@kajangnanasakthy2439]

Just used this to really make my galaxies pop! I took pictures of m81 and m82 and and was really bothered i couldn't really separate the galaxy from the grey background (i live in a bortle class 5). This tutorial really gave me that ability!...oh and i knew nothing about photoshop until a month or so ago. THANK YOU TREVOR!

[@shantonudutta9726]

Thank you very much! This made a great difference to my photos taken from a starter smartphone camera (and it can't take RAW images). So after stacking, there was some serious gradient issues. But this method worked greatly for me :D

[@deepskydiving8940]

Thank you!!! Exactly what I am looking for!!!!

[@nilaya80]

Nice this will sure come in handy someday! What resolution do you set in your camera when you capture images ?

[@dalep2842]

This is what i have wanted to do but I use Gimp. Any suggestions for how to do it in Gimp?

[@ltsMadn]

Again great image!! This will come in handy. Thank you for the tutorial!!

[@AstroBackyard]

My pleasure. Thanks!

[@MrSkySharks]

This was awesome. thanks :)

[@expediteplanb7443]

Another way is to simply duplicate the image, clone stamp, Gaussian blur, apply image. Easy peasy. Is it me, or did you also have some banding issues going on in your image? Either way, like your vids. Keep it up.

[@AstroBackyard]

Thanks for that! Yeah, when viewing on a bright monitor you can really see the impurities of the background sky. I really think the main issue is shooting into heavy LP without any sort of filter.

[@FarmLapse]

So I'm trying to do this with an orion image and when using the alt key method and brushing over orion, it's just WAY too dark.

[@FarmLapse]

Also getting banding

[@peterbucek2136]

This is brilliant! Thank you very much, I will surely try this!

[@konrak81]

great video like always

[@PraktycznieWiem]

thank you, great, clean tutorial

[@WaervynsWorld]

Brilliant, thanks a lot! :)

[@nueschi]

Brilliant, thanx! 😎

[@317stinky]

This is a game changer!!!!

[@thechristianpianist864]

WOW literally life saver

[@sudhendrakambhamettu]

thats totally cool!! ;) ..thank u!!

[@ivoandricic1088]

lol unrelated but my view was 6969th btw love your videos, i learned a big part of everything i know about astronomy and astrophotography from you! Thank you!

[@AstroBackyard]

Thanks brother so glad to hear that

[@uanesdeiro]

Thank!!!

[@ozzmozizz22]

An other great video

[@stevenrobinsonpictures]

I'm finding this "works", but also removes all the faint signal and details in the background.

[@geodezix]

what is a gradient?

[@spacedogsbackyardastronomy8274]

i guess nobody wants to tell us!!!!!!!

[@emflocater]

Lost me when I clicked the play button!

[@junsupark2904]

I love you

[@gabewrsewell]

This is black magic

[@TheVanhow]

Bullshit!